DIY Retractable Awning This would just be hung on an existing pergola. Looks like it would be two shower curtain tracks, curtain rods hung across... honestly the most pain would be sewing the canopy part out of canvas... oh yeah, and building a pergola
Shade sails are designed to provide outdoor protection from the sun and use a flexible membrane, tensioned between three or more anchor points, similar in form to a ships sail, hence the name. Sun canopies and sun awnings are designed to provide the same protection but are just slightly different in concept. This article discusses all three.